Bump to 0.5.1

Author: Kreozot

package.json

@@ -8,7 +8,7 @@
     "generator"
   ],
   "homepage": "https://github.com/millermedeiros/mdoc.git",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "author": {
     "name": "Miller Medeiros",
     "url": "http://blog.millermedeiros.com/"